poliaddizione

Poliaddizione is a type of polymerization reaction where monomers add to one another in such a way that the resulting polymer chain contains repeating units derived from the monomers. Unlike polycondensation, which involves the elimination of a small molecule like water or alcohol, poliaddizione reactions proceed without the loss of any atoms from the reacting monomers. The addition of monomers occurs without the formation of byproducts.

The mechanism of poliaddizione can vary. Common types include anionic, cationic, and radical polymerization. In anionic polymerization, monomers with electron-withdrawing groups react with nucleophiles. Cationic polymerization involves monomers with electron-donating groups reacting with electrophiles. Radical polymerization, a widely used method, initiates with the formation of free radicals that propagate by adding to monomer units. Coordination polymerization, often employed for the synthesis of stereoregular polymers like polypropylene, utilizes metal-containing catalysts to control the addition process.

The resulting polymers from poliaddizione often have high molecular weights. The repeating units in the polymer chain are essentially the intact monomer molecules. Examples of polymers produced via poliaddizione include polyethylene, polypropylene, polystyrene, and polyvinyl chloride. The specific type of polymerization mechanism employed dictates the structure, properties, and potential tacticity of the final polymer. This polymerization method is a cornerstone of polymer science and industrial polymer production.